JPS5816001A - Production of ferromagnetic powder consisting essentially of iron - Google Patents

Abstract

PURPOSE:To obtain ferromagnetic powder which consists essentially of iron, is easy to handle and is highly stable even in air by immersing the magnetic powder obtd. by immersing the magnetic powder consisting essentially of iron in an org. solvent then removing the solvent, again in the org. solvent. CONSTITUTION:The magnetic powder which consists essentially of iron and is obtained by reducing a metallic compd. consisting essentially of iron (e.g.; ghoethite) in a reducing atmosphere is treated in the following way: Said magnetic powder is immersed in an org. solvent (e.g.,; arom. hydrocarbons) of the amt. of >=1/1, more particularly 2/1 weight ratios with respect to said powder. The org. solvent is evaporated away by taking preferably a long time, generally, 12- 100hours in ordinary air. The magnetic powder removed of the solvent is further immersed in the org. solvent, whereby the intended ferromagnetic powder is obtd. The ferromagnetic powder is suitable for magnetic recording media such as magnetic tapes and magnetic discs.

Description

【発明の詳細な説明】 本発明は鉄ｋｆ、成分とする強磁性粉末の製造方法に関
し、更に詳しくは、磁気テープ、磁気ディスク、磁気ド
ラム勢の磁気記鎌媒体に遍した磁性粉末の製造方法に関
する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a ferromagnetic powder containing iron kf as a component, and more specifically, a method for producing a magnetic powder for use in magnetic recording media such as magnetic tapes, magnetic disks, and magnetic drums. Regarding.

磁気記録媒体に用いられる鉄を主成分とする惣ｉ性粉末
（本明細書において鉄を主成分とする強磁性役末とは、
少なくと４　ｊ　Ｏｗ　を嘔の鉄を含む強磁性粉末を意
味する）は針状粒子であシ、その粒ＩＩ（短軸方向）は
ｔｚｏ−ｚｏｏｈで、軸比は３〜ｌ！の範囲内と非常に
微細な粒子である。又比表面積Ｆ１８　　ＢＥＴでＪｊ
以上、好ましく扛Ｊａｍ”／を以上有している。Ferromagnetic powder containing iron as the main component used in magnetic recording media (in this specification, ferromagnetic powder containing iron as the main component)
The ferromagnetic powders containing at least 4 j Ow of iron are acicular particles whose grains II (minor axis direction) are zo-zooh and have an axial ratio of 3 to 1! within the range and very fine particles. Also specific surface area F18 Jj with BET
As mentioned above, it is preferable to have 扛Jam''/ or more.

かかる鉄を主成分とする強磁性粉末の製造方法としては
％　（１１１１磁性金属の有機酸塩ｋｍ熱分鵡し、還元
性気体で還元する方法と、（２）針状オキシ水酸化物或
いはこれに他Ｏ金属を含有させたもの或いはこれらのオ
キシ水酸化物から得た針状酸化物上還元すゐ方法に大別
できる。Methods for producing such ferromagnetic powders containing iron as a main component include (2) acicular oxyhydroxide or acicular oxyhydroxide. It can be roughly divided into methods in which O metal is added to the oxyhydroxides, and methods in which reduction is performed on needle-like oxides obtained from these oxyhydroxides.

これちの方法によシ得られた鉄を主成分とする強磁性粉
末は発火性が強いため、その１１壇！気中にＩＩＩＬシ
出す仁とは非常にむりかしく、鉄を主成分とする強磁性
粉末會空気中で安定にするために主々な改良方法、例え
は、組ＩＫ、會改良することにより安定化させる方法（
特公昭１１−１４０１号、Ｕ８Ｐ１，７８１．１ｆｔ勢
）カ提案さｔしてｈ！。The ferromagnetic powder whose main component is iron obtained by these methods is highly flammable, so this is the 11th! It is very difficult for a ferromagnetic powder mainly composed of iron to be released into the air.The main methods of improvement are to stabilize the ferromagnetic powder in the air. How to make it (
Special Publication No. 11-1401, U8P1,781.1ft) has been proposed! .

１７に、鉄を主成分とする強磁性粉末の表１１に保襲膜
を設けることによ〕化学的に安定化する方法（％公開ｊ
Ｊ−７弘ｔＶｔ号、特開昭−デー／Ｊ１１１１号、特開
開−デー９７７１１号、特開昭４１−１０１γ号勢）も
提案されている。17, a method of chemically stabilizing the ferromagnetic powder containing iron as a main component by providing a protective film in Table 11 (% disclosure)
J-7 KotVt, JP-A No. 1111, JP-A No. 97711, and JP-A No. 101-101) have also been proposed.

しかし、これらの方法でもなお磁性粉末の長期保存には
問題があり、従って磁気特性、特に飽和磁化（δ３）及
び抗磁力（Ｈｅ）が劣化又社変動する傾向は未だ充分に
屏決されていない。However, even with these methods, there are still problems with long-term storage of magnetic powder, and therefore, the tendency for magnetic properties, especially saturation magnetization (δ3) and coercive force (He) to deteriorate or change, has not yet been fully determined. .

本発明の目的は、第１に、これらの欠点會改良し、取扱
いが容易でかつ空気中においても安定性の高い鉄を主成
分とする強磁性粉末１ｍ造する方法を提供するととにあ
シ、第２Ｋ、磁気記鍮媒体用として優れた磁気特性ｔ１
１する強磁性粉末ｖｔ提供することにある。The first object of the present invention is to overcome these drawbacks and provide a method for producing 1 m of ferromagnetic powder mainly composed of iron, which is easy to handle and highly stable even in air. , 2nd K, excellent magnetic properties t1 for magnetic recording brass media
The purpose of the present invention is to provide a ferromagnetic powder VT.

本発明者達は上述した安定化方法上検討した結果、安定
化された強磁性粉末においても９気中で乾燥状態で放置
した場合、少量の場合は比較的安定であるが、工業的ス
ケールで大量に扱う場合は、短時間で斃熱が起シ、それ
が蓄熱されて昇温し、最悪の場合は、急速な酸化反ＦＥ
ｈが起シ、酸化鉄に変化してしまうこと、及びこの傾向
拡、一時的に密閉し先後、或いは保管中に移動させて強
磁性粉末に振動を与え次後に、空気中＋敵機うと急道酸
化し易いことを発見し斥。As a result of the above-mentioned stabilization method, the present inventors found that stabilized ferromagnetic powder is relatively stable in small quantities when left in a dry state in 9 atmospheres, but on an industrial scale. When handling a large amount, heat will occur in a short time, and the heat will be stored and the temperature will rise, and in the worst case, rapid oxidation and anti-FE will occur.
The ferromagnetic powder is caused by ferromagnetic powder, which changes into iron oxide, and this tendency spreads. He discovered that it was easily oxidized.

本発明者達は上記の知見に基いて更に研究１重ねた結果
、本発明の上記の１的は、従来知られた方法で得られた
鉄ｔ！！成分とする磁性粉宋音、従来知られた方法て溶
媒に浸漬し、従来知られた方法で溶媒を除去して得られ
る乾燥した鉄を主成分とする磁性粉末【、更に有機溶媒
に浸漬することＫよって達成されゐことを見い出した。As a result of further research based on the above knowledge, the present inventors found that the above first objective of the present invention was obtained using iron t! ! Dry magnetic powder containing iron as a main component obtained by immersing the magnetic powder in a solvent using a conventionally known method, and removing the solvent using a conventionally known method, and further immersing it in an organic solvent. I found that this was achieved by K.

加熱還元して得られた鉄を主成分と丁ゐ強磁性粉宋音通
常そのまま乾いた状態で取出すことは該粉末の活性が強
いため困難で、有機溶媒に浸漬して取出すのが一般的で
あゐ、この際、便用する有機溶媒は、選択されるべ１で
あ夛ケトン類、エステル拳、ハ冒ゲン化嶽化水素類は該
粉末Ｏ触媒作用によ〉分堺される可能性があｐ注意が必
要である。好壕しくに芳香ｍ炭化水素類、環状炭化水素
類、直鎖状炭化水嵩−であ為、該有機溶媒０ｆａｒ量は
、磁性粉末に対する有機溶媒の量が重量部で／／／ｓ好
ＩＬ＜はＪ／／より多くなるよう感層することが、次工
程で乾燥させ穴とき、磁性粉末の安定性は良好となる。The main component of iron obtained by thermal reduction is ferromagnetic powder.It is difficult to extract it in a dry state as it is because of the strong activity of the powder, so it is common to extract it by immersing it in an organic solvent. Ah, at this time, the organic solvent to be used should be selected, and there is a possibility that the ketones, esters, and hydrogenated hydrogen oxides will be separated by the powder O catalytic action. However, caution is required. Preferably, aromatic hydrocarbons, cyclic hydrocarbons, and linear hydrocarbons are used. When the magnetic powder is sensitized so that it is larger than J//, the stability of the magnetic powder becomes better when it is dried in the next step.

磁性粉末に対する有機溶媒の比率が／／／よｐ少なくて
もよいが、次工程での安定性に欠けるので注意が必要で
ある。ｔた、Ｖ機ｓ線に可溶な界Ｗ＠性剤、滑剤、分散
剤等【ＪＯｗｔ％以下で金層させてもよい。The ratio of the organic solvent to the magnetic powder may be lower than ///, but care must be taken as this may lack stability in the next step. In addition, an interfacial agent, a lubricant, a dispersant, etc. soluble in the V-machine s-ray may be used as a gold layer in an amount of JOwt% or less.

次いで、＃有機溶媒を除去する工１であるが、通常空気
中で長時間かけて蒸発させるのが好ましい、一般的に扛
、７２時間〜１００時間で？＆環するのが好ましい、Ｖ
機溶媒會強磁性粉末に対して大量に用いた場合は、あら
かじめ、フィルタープレス等で過剰の有機溶媒！除去し
たのち、蒸発させればよい。Next, step 1 is to remove the organic solvent, but it is usually preferable to evaporate it in air for a long time, generally for 72 to 100 hours. & Preferably, V
When using a large amount of organic solvent for ferromagnetic powder, remove excess organic solvent using a filter press, etc. in advance! After removing it, it can be evaporated.

蒸発さぜる＃囲気ｉｔ空気中でよいが、駿累濃度會適宜
コン）ａ−ルしてもよい、処ｍｌｌ１Ｉ″は特に制限さ
れないが、一般的にｎＯ’ｃ−ｊｏｏＣの範囲内でよい
。Evaporation may be carried out in the air, but the cumulative concentration may be controlled as appropriate. The treatment is not particularly limited, but may generally be within the range of nO'c-jooC. .

乾燥級、Ｊｏｏ”Ｃ以内まで加熱することも可能である
が、昇ｉＩはｔｏ”Ｃ７時間以内で行なう仁とが好まし
い、ＩＥ燥状態とは、有機溶媒介がｌＯ重重量縁下であ
本かつ水分が１重量憾以下會意味する。Although it is possible to heat to within 7 hours to dry grade, it is preferable to heat to within 7 hours. And the water content is less than 1 weight.

本発Ｖｉ４における鉄を主成分とする強磁性粉末とは、
費末のｔｏ重量暢以上が金属分でＴｏＬ該金属分の！Ｑ
〜／ＩＩＩ重量参が鉄であｐ１他に０〜コＯ重量嘔のニ
ッケル、コバルトおよびＯ〜１０重量暢重量−ム、マン
ガン、憂鉛およびＯ〜！重量重量子ル１ニウム、ケイ票
、リン、ホウ素、銅、銀、ビスマス、鉛、スズアンチモ
ン、イオウＯいずれ−ｘＰ１つ又は１つ以上が単ａもし
くは複数で含まれてもよい。The ferromagnetic powder whose main component is iron in the present invention Vi4 is
At the end of the cost, the to weight or more is the metal portion, and the ToL metal portion! Q
~ / III weight is iron, p1 and 0 ~ coO weight 0 nickel, cobalt and O ~ 10 weight - um, manganese, eupyrite and O ~! One or more of the following may be included in the form of a single a or plurality of gravimetric luium, phosphorus, boron, copper, silver, bismuth, lead, tin antimony, and sulfur O.

本発明の強磁性粉末の粒径（短軸方向）は／７る。軸比
は１〜１２の範囲で、比表面積扛コｊ１％”／２〜りＯ
Ｗ＠”　／　ｔｓ好ましくはＪａｍ”／ｌ１−４ｏ”７
ｔである０強磁性粉末の表面は、酸素、窒票尋の化合物
るるいは１機化合物の層で被援されることができる。The particle size (minor axis direction) of the ferromagnetic powder of the present invention is /7. The axial ratio is in the range of 1 to 12, and the specific surface area is 1%/2 to 1%.
W@”/ts preferably Jam”/l1-4o”7
The surface of the ferromagnetic powder can be coated with a layer of oxygen, nitrogen, or monomer compound.

乾燥した強磁性粉末ＫｌｊＫＷ機溶媒を含浸させること
が本発明の特に重要な１薯である。従って、使用する有
機溶媒は４＋１に制限されず、通常の如何なる有機溶媒
４ｈ使用できる。たとえば、有機Ｓ厳重含浸させる次の
工１ｉＫ都合の良い溶媒を必要量含浸させればよい、又
、有機溶媒に可溶な界面活性剤、滑剤、分散剤勢【好ま
しくは２０重量−取木発明の効果【期待することはでき
ない、Ｖ機溶媒量が強磁性粉末に対して、約を重量部以
下では、外皺上乾燥状診と同じであル、又、取扱い上も
乾燥した強磁性粉末と同様に取扱うことが可能であるｅ
ｔＰ＜ｔ、、て得られた本発明による鉄を主成分とする
強磁性粉末は、豐閉状−で長時間保存しｔ４合、或いは
保管中に強磁性粉末に振動が与えられたりした場合にお
いても、その後空気中にとり出しても従来の強磁性粉末
にくらべて安定であシ、取シ扱いが容易である。このこ
とは、鉄【主成分とする強磁性扮宋音工業的に取扱う上
で特に重要なことであシ、結合剤勢と混合分散し、磁気
記録媒体を勧進する次工程へ安定して移行させること又
強磁性粉末に含浸される有機溶媒が適宜自由に選択でき
るため、磁気記録媒体【作る工１は制約を受けず、所望
の磁気記録媒体を得ることができる。更に１磁気記録媒
体において、その主要素材である強磁性粉末が安定であ
るため、経時による特性変化の改善ができる。又仁の技
衝け、他の製法（ＩＰｌえは、ボーハイドライド法、金
属カルｉニル化合物の熱分解法、低圧不活性ガス中での
蒸発法等）Ｋよシ得られた強磁性金属粉についても利用
できる。Impregnating the dry ferromagnetic powder KljKW with a solvent is a particularly important aspect of the present invention. Therefore, the organic solvent used is not limited to 4+1, and any conventional organic solvent 4h can be used. For example, in the following step of strictly impregnating organic S, it is sufficient to impregnate a necessary amount of a convenient solvent, and also a surfactant, a lubricant, a dispersant soluble in an organic solvent (preferably 20% by weight). The effect [cannot be expected] is that if the amount of solvent is less than about 1 part by weight for the ferromagnetic powder, it is the same as the dry symptom diagnosis on the outer wrinkles, and it is also difficult to handle the dry ferromagnetic powder. It is possible to handle it in the same way as e.
The ferromagnetic powder containing iron as a main component according to the present invention obtained when tP<t, is stored for a long period of time in a closed shape, or when the ferromagnetic powder is subjected to vibration during storage. It is also more stable than conventional ferromagnetic powders even after it is taken out into the air, and is easier to handle. This is particularly important when industrially handling iron as a ferromagnetic material, which is mixed and dispersed with a binder and stably transferred to the next process of forming a magnetic recording medium. Furthermore, since the organic solvent with which the ferromagnetic powder is impregnated can be freely selected, the magnetic recording medium manufacturing process 1 is not subject to any restrictions and a desired magnetic recording medium can be obtained. Furthermore, since the ferromagnetic powder that is the main material of the magnetic recording medium is stable, changes in characteristics over time can be improved. The ferromagnetic metal powder obtained using Matahito's techniques and other manufacturing methods (IPl is the bohydride method, thermal decomposition method of metal carbonyl compounds, evaporation method in low-pressure inert gas, etc.) It can also be used for

以下に本発明を実施例によシ更に具体的に説明する。The present invention will be explained in more detail below using examples.

実施例　Ｌ ＺｔＩ（ＯＲ）ＩＪ重量鳴とＮ１（ＯＨ）！ｚ重量ａｔ
付着させた比＊Ｗ＊がＩ’１ｗｒ／ｆＯゲータイ）？出
発原料として通常の方法によシ鉄を主成分とする磁性粉
末！調製した０次いでＮ３中て強磁性粉条【強磁性粉ｌ
に対してトルエン参の割合で浸漬して空気中にＷＩｌシ
出した。Example L ZtI (OR) IJ weight sound and N1 (OH)! z weight at
The attached ratio *W* is I'1wr/fO gametai)? Magnetic powder whose main component is iron, prepared using the usual method as a starting material! The prepared ferromagnetic powder strip [ferromagnetic powder l
It was immersed in toluene and ginseng at a ratio of 300 to 300 ml, and then poured into the air.

次いで、フィルタープレスで過剰のトルエン【しぼった
のち、コｊ　’Ｃ，１０嚢ＲＨの１＃囲気の空気中で弘
１時間トルエンを蒸発させ乾燥した強磁性粉末【得た。Next, the excess toluene was squeezed out using a filter press, and the toluene was evaporated for 1 hour in the air of 1# atmosphere of 10 bags of RH to obtain a dried ferromagnetic powder.

この強磁性粉末の特性は、比表面積がｊｕｌ’Ｆｌ”／
　ｆ　ｓ　Ｈｃ　／　Ｊ　００　Ｃ）ａ　＊δ、　ｔ　
ａ　Ｉ　ｅｍｕ／ｆ　ｅａｔ／ａｓｈ、ｊｏであつ＊（
Ｈｍ＝ｔｏＫ（Ｊａで詰率０．１２で測定）。The characteristics of this ferromagnetic powder are that the specific surface area is jul'Fl''/
f s Hc / J 00 C)a *δ, t
a I emu/feat/ash, jo de atatsu*(
Hm=toK (measured at a packing rate of 0.12 in Ja).

組ＩｉＬはＦ　ｅ　ｒ弘、σ重量部、Ｎ五コ、２重量部
、Ｚｎ１．り１量暢であった。又水分はｏ、を重量部含
有していた。Group IiL contains Ferhiro, σ parts by weight, N5, 2 parts by weight, Zn1. He was fluent in one quantity. In addition, the water contained part by weight of o.

（１１上記の乾燥した磁性粉弘麺會ビニール袋に入れ、
口會閉め、石油缶に納め密閉してｌＱ日間保存した（サ
ンプルＡ）。(11 Place the above dried magnetic powder in a plastic bag,
The container was closed and the container was sealed and stored in an oil can for 1Q days (Sample A).

（２）上記乾燥した磁性看各参麺ｔビニール袋に入れ、 １）その中にメチルエチルケトンｒｏｏｔｋＺｌＯえて
口會閉め、石油缶に納め密閉して１０日間保存した（サ
ンプルＢ）。(2) The dried magnetic noodles were placed in a plastic bag. 1) Methyl ethyl ketone root ZlO was added thereto, the bag was closed, and the bag was sealed and stored in an oil can for 10 days (Sample B).

雪）１）　においてメチルエチルケトンＪＫ４ｉ加えた
他は１）　と同様（サンプルＣ）。Snow) Same as 1) except that methyl ethyl ketone JK4i was added in 1) (Sample C).

３）１）においてメチルエチルケトンｐ４會加えた他は
１）と同様（サンプルＤ）。3) Same as 1) except that methyl ethyl ketone p4 was added in 1) (Sample D).

４）１）　においてメチルエチルケトン１０時ｉ加えた
他は１）と同様（サンプルＥ）。4) Same as 1) except that methyl ethyl ketone was added at 10:00 in 1) (sample E).

１）１）にお−てメチルエチルケトンの代９に酢酸−一
プチル會用いた他は冨） と同じ（サンプルＦ）。1) Same as 1) except that monobutyl acetate was used in place of methyl ethyl ketone (sample F).

（３）上記乾燥し曳磁性粉参に４を約ｌ講　のパットに
広けて空気中に１０日間放置した。ｌ０日１１Ｋ（１１
と同じ方法でビニール袋に入れ、石油缶に納め開放した
くサンプルＧ）。(3) 4 was spread on the dried magnetically powdered powder in a pad of about 1 cm and left in the air for 10 days. 10 days 11K (11
I would like to put it in a plastic bag using the same method as above, put it in an oil can, and then open it (Sample G).

次に／　ＯＥｌ倹に上ＩＥＡ　〜ＧＯｔンプルｔ−Ｊ　
ＪｏｃＡＪ４７１１Ｂ）］の雰囲気の９！気中に開封し
温度計【サンプル上部よりｊ菌の位１１に差し込み温度
変化を測定した。Next / OEL thrift top IEA ~ GOt sample t-J
JocAJ4711B)] atmosphere 9! The sample was opened into air and a thermometer was inserted from the top of the sample into position 11 of J bacteria to measure the temperature change.

結果は第１ＷＡに示す過ｐである。The result is the excess p shown in the first WA.

サンプル人は鉄會主成分とする乾燥磁性粉末を１０日゛
間密閉して保存したのち空気中で開封した時の発熱状１
Ｉｔ−示し穴ものである。開封後短時間で急激な昇温が
起り、約２０＠ｃで急激な酸化反応が生じ磁性粉末は発
火しく炎は出ないが炭がおきた状態）、茶色の酸化鉄に
変色してしまった。In the sample, the dry magnetic powder containing iron powder as the main ingredient was stored in a sealed container for 10 days and then opened in the air.
It- It's a hole thing. A rapid temperature rise occurred in a short period of time after opening the package, and a rapid oxidation reaction occurred at approximately 20°C, causing the magnetic powder to catch fire (no flames were emitted, but charcoal was formed), and the color changed to brown iron oxide. .

一旦、空気中で安定になっても長期間密閉状態で保管し
ておくと、その間に磁性粉末の表ｒＩｉＫ存在していた
酸素が内へ移動する轡の変化が起り、磁性粉末の表面が
再び活性化されたものと考えられる。Once it becomes stable in the air, if it is stored in a sealed state for a long period of time, the oxygen that was present on the surface of the magnetic powder will move inward, and the surface of the magnetic powder will change again. It is thought that it has been activated.

サンプルＢは、サンプルＡはどではないが中はや昇温し
、開對後一時間半でやＦｉ多急速な酸化が起シ茶色に変
色した。Sample B did not have the same temperature as Sample A, but the temperature rose quickly, and the color changed to brown due to rapid oxidation of Fi within an hour and a half after opening.

サンプルＣ−Ｇは昇温速度は非常にゆるやかであり、開
封後次工程のテープ化の為の作業において、安全ＫＮ扱
うことが可使である。Sample C-G has a very slow temperature rise rate, and can be safely handled with KN in the next step of tape production after opening.

但し、サンプルＧは経時による温度変化は非常に少いが
、磁性粉末中の水分が、コ、ｊ鳴含まれており、その１
１テープ化すること拡、分散不良を生じる尋の開動があ
ル不可能である。その為何婢力０手段によシ除湿操作が
必要ｔなシ、工業的に実施するのは設備化が必要となる
。However, sample G has very little temperature change over time, but the moisture in the magnetic powder contains some noise.
It is impossible to widen the tape into a single tape, and there is no opening movement that would cause poor dispersion. Therefore, it is necessary to perform a dehumidification operation by a means that requires no energy, and industrial implementation requires equipment.

含浸しているが、乾燥磁性粉と１ｉｌｌｌな操作で取扱
うことが可能であｐｌなお乾燥は磁性粉（サンプルＡ）
より、空気中で安定であｐ発熱も少いため、テープ化の
為の手段は輻広く利用できる利点がある。Although it is impregnated with dry magnetic powder, it can be handled in the same way as dry magnetic powder (sample A).
It is more stable in the air and generates less p-heat, so the tape-forming method has the advantage of being widely usable.

本発明の爽施鯵様を挙げれば以下の如くである。Examples of the Souse horse mackerel of the present invention are as follows.

１１１　　％許請求の範囲において、加熱還元して得ら
れた鉄４Ｌ＜は鉄を主成分とする磁性粉末を芳香ｆｊ嶽
化水票に含浸させる方法。111% In the scope of the claim, iron 4L< obtained by thermal reduction is a method of impregnating an aromatic fj water slate with magnetic powder containing iron as a main component.

（２、特許請求の範囲において、１機溶媒を除去して乾
燥した磁性粉末を得る工程で乾燥した磁性粉末は水分が
１重量鳴以下であｐ、δ易が／１０　ｅｍ璽／ｆ以上で
ある方法。(2. In the claims, the magnetic powder dried in the step of removing the solvent and obtaining the dried magnetic powder has a water content of less than 1 weight p, and a delta yield of /10 em/f or more. A certain way.

（３；　　特許請求の範囲において乾燥した磁性粉末に
１機溶媒を含浸させる工程において、ｗＩ庸横機溶媒磁
性粉末に対し、ＪＯ１量噛以上會浸させることｔ−％像
とする方法。(3; In the step of impregnating the dry magnetic powder with a single solvent in the claims, a method in which the wI horizontal machine solvent magnetic powder is impregnated with at least one amount of JO is t-%.

【図面の簡単な説明】[Brief explanation of drawings]

第１ＷＡは実施ｆ％ＩＯ各サンプルの空気中での経時時
間とａ度上昇髪示すグラブである。 特許出願人　　富士写真フィルム株式会社第１図The first WA is a grab showing the run time and a degree rise of each sample in air. Patent applicant Fuji Photo Film Co., Ltd. Figure 1

Claims (1)

【特許請求の範囲】[Claims] 鉄を主成分とすると金属化合物を還元性雰囲気中で、加
熱還元して得られた鉄を主成分とする磁性粉末ｔ１磁性
粉に対する１機＃ｌＪＩの量がｌより多い状態になるよ
うに、有機溶媒に含浸させ、有機溶媒を除去して乾燥し
た強磁性粉末とし、更に有機溶媒を含浸させることを特
徴とする鉄を主成分とする強磁性粉末の製造方法。If iron is the main component, magnetic powder t1 whose main component is iron obtained by thermal reduction of a metal compound in a reducing atmosphere, so that the amount of JI per machine is greater than l. A method for producing a ferromagnetic powder containing iron as a main component, which comprises impregnating it in an organic solvent, removing the organic solvent to obtain a dried ferromagnetic powder, and further impregnating it with an organic solvent.